All three men were charged with seeking sex for a fee. Fox was also charged with possessing prescription medication with intent to distribute.

Most defendants agreed to pay $200 or more for sex when they contacted Boston Police online, but Fox allegedly offered to pay with Gabapentin, a prescription medication sometimes used as a tranquilizer, Conley said.

Romanak was released on personal recognizance after his arraignment Tuesday in South Boston Municipal Court. He is due back in court on April 2.

Plyant and Fox were arraigned in Boston Municipal Court on Jan. 29. Fox posted $200 bail and is due back in court on April 15. Plyant was released on personal recognizance and is due back in court on May 5.

Conley's office and the state's Interagency Human Trafficking Policy Task Force have called for a first-offender program or "john school" like those used in other states, but such a program has yet to be started in Massachusetts.

"Research consistently shows prostitution to be linked with violence, coercion, sexual assault, and drug addiction," Conley said. "The average age of entry into the sex trade is in the young teens. Our diversion programs for exploitation victims are nationally recognized, but the other side of that strategy is reducing demand through stings like this one."

In recent years, Boston police have shifted from a model targeting those working as prostitutes to one that seeks to drive down demand by targeting johns. Suffolk prosecutors are seeking penalties that are stronger for those who buy or seek to buy sex than those with similar criminal histories who sell or seek to sell it, Conley said.

In a landmark 2006 policy shift, Conley voluntarily adopted a "safe harbor" policy for prostituted youth, treating them as victims of exploitation rather than offenders. That voluntary policy was later expanded statewide in Massachusetts' 2011 human trafficking legislation.

Conley's office also directs the Support to End Exploitation Now program, a multi-agency task force that connects young exploitation victims with services.

Maria Papadopoulos may be reached at mpapa@enterprisenews.com or follow on Twitter @MariaP_ENT.